An actuator system of the character to be described may be used very efficiently to move heavily loaded floors, decks and shelves in the high density storage facilities where relatively heavy loads are to be moved. Typically, the supporting structures for such movable load elements are large and fabricated of mass produced structural members, and are not precision manufactured. To the inventor's knowledge nothing of the character to be described herein has been used to provide and overcome the problems encountered in moving such heavy loads. It is believed that scissors jacks have previously been used but, of course, these are not very versatile, smoothly operating actuators which readily self align and can be so readily and economically installed.